We've got an exclusive look at the "holy grail" of superhero footage from the development of the Tim Burton Superman movie that never was. Titled "Superman Lives," the late 1990s project may be dead, but the Burton Superman shall live on forever in our hearts and minds in this video of Nic Cage doing stretches in his tight, shiny Superman suit.

The footage is from the documentary "The Death of 'Superman Lives': What Happened?" created by director Jon Schnepp in hopes of finding out what derailed this legendary unmade film. Schnepp interviewed (just about) everyone associated with "Superman Lives," from costume designer Colleen Atwood and the director's assistant Derek Frey (both seen in the above clip) to director Tim Burton. The interviews, combined with exclusive concept art and the amazing behind-the-scenes footage of Cage in Superman mode, paint a pretty good picture of what could have been, and it would have been insane. But that good kind of Burton insane. Probably.

"The Death of 'Superman Lives': What Happened?" isn't all just Cage doing super calisthenics; the documentary also puts a lot of long-held "Superman Lives" rumors on blast. For example, the lightning super suit (seen above) was not going to be used for the entirety of the film. There would be no rainbow lightbrite Superman -- a fact that Schnepp clears up. According to the documentary, that suit was made for a singular moment early on in the film.

And as you can see, the suit Cage is punching abou in is a slightly darker shade of blue from the traditional suit, similar to the actor's long, black hair. A darker Superman, if you will. Emo Supes.

"The Death of 'Superman Lives': What Happened?" will be available on DVD, Blu-ray and video on demand on July 9 only through the documentary's website or at booth #3915 at San Diego Comic-Con. So check it out and get the whole story from the actual people who worked on the film. Including screenwriter Kevin Smith.